Printing technology has been adapted for purposes beyond printing words and graphics on paper. Many advances involve integrating printing devices, such as ink jet printers and roll-to-roll printers, into known processes to generate new, more effective methods. For example, ink jet technology has been used in high-affinity chemical sensors to deposit the high-affinity material on a sample in a more precise and controlled manner than previous techniques. In another example, piezoelectric inkjet print heads have been used to deposit light-emitting polymers on flat panel displays. Roll-to-roll printing systems have been used to generate electronic circuits. In general, a roll-to-roll printing apparatus can be employed to print circuit lines on a flexible substrate using conductive, metal-based inks.
Pairing conventional printing processes with conductive inks is a potentially cost-effective method for mass producing electronic devices. Consequently, the printed electronics market is predicted to grow about ten-fold over the next decade, particularly for applications involving flexible displays and radio-frequency identification (RFID) elements. However, this growth may be hampered by certain inefficiencies arising in the printing of electronic circuits and other electronic elements. For example, misalignment of the substrate during printing may render an entire printed circuit unusable. Conventional printing systems are not capable of adequately detecting misalignment until the printing process is complete, resulting in increased processing costs and manufacturing time. Accordingly, printing processes will not be able to scale to cost-effectively mass produce printed electronics until such inefficiencies can be addressed before and during the printing process.